No platinum coins were struck in 1879, the first ones were in 1997

If you mean an 1879 Morgan with no mintmarks, the coin is common. Circulated examples are $30.00-$37.00. Mint State coins are $40.00-$50.00

The 1879 Morgan dollar is not scarce or rare, assuming it's circulated and has no mintmark, average retail values are $26.00 to $32.00 depending on how much wear the coin has.

It's a fake Trade Dollar, 1879 Trade Dollars are proof only issues that were struck in Philadelphia and have no mint mark

5-3-11>> Assuming the coin is circulated and has no mintmark, the 1879 Morgan dollar is a very common coin with retail values of $38.00-$44.00 depending on the grade of the coin.